So I don't see this anywhere as a recommendation to use and yet, to me at least, it seems like a no-brainer. 3% haste all the time as opposed to 30% haste for 20s every two minutes seems like a good deal. Sure, you lose the benefit while on cooldown but it's a benefit you wouldn't be getting anyway without the glyph, so using DS: Misery every 2minutes for a 27% haste buff doesn't seem like a net loss to me.
Is there some reason that this is considered a bad glyph that I'm missing or is it just that people haven't updated guides yet to suggest this glyph?